<!DOCTYPE html
  PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">

<head>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>大转盘活动</title>

  <link href="style.css" rel="stylesheet" type="text/css">

</head>

<body style="background:#f5f5d5;overflow-x:hidden;">
  <div class="title"></div>
  <img src="images/1.png" id="shan-img" style="display:none;" />
  <img src="images/2.png" id="sorry-img" style="display:none;" />
  <div class="banner">
    <div class="turnplate" style="background-image:url(images/turnplate-bg.png);background-size:100% 100%;">
      <canvas class="item" id="wheelcanvas" width="422px" height="422px"></canvas>
      <img class="pointer" src="images/turnplate-pointer.png" />
    </div>
  </div>
</body>

<script type="text/javascript" src="js/jquery-1.10.2.js"></script>
<script type="text/javascript" src="js/awardRotate.js"></script>

<script type="text/javascript">
  var turnplate = {
    restaraunts: [],				//大转盘奖品名称
    colors: [],					//大转盘奖品区块对应背景颜色
    outsideRadius: 192,			//大转盘外圆的半径
    textRadius: 155,				//大转盘奖品位置距离圆心的距离
    insideRadius: 68,			//大转盘内圆的半径
    startAngle: 0,				//开始角度

    bRotate: false				//false:停止;ture:旋转
  };

  $(document).ready(function () {
    //动态添加大转盘的奖品与奖品区域背景颜色
    turnplate.restaraunts = ['周澈','周硕','周沁','周念','周文','周雯','周浦','周梓欣','周洲'];
    turnplate.colors = ["#FFF4D6", "#FFFFFF", "#FFF4D6", "#FFFFFF", "#FFF4D6", "#FFFFFF", "#FFF4D6", "#FFFFFF", "#FFF4D6", "#FFFFFF"];

    if (turnplate.restaraunts.length == 0) {
    }

    var rotateTimeOut = function () {
      $('#wheelcanvas').rotate({
        angle: 0,
        animateTo: 2160,
        duration: 8000,
        callback: function () {
          alert('网络超时，请检查您的网络设置！');
        }
      });
    };

    //旋转转盘 item:奖品位置; txt：提示语;
    var rotateFn = function (item, txt) {
      var angles = item * (360 / turnplate.restaraunts.length) - (360 / (turnplate.restaraunts.length * 2));
      if (angles < 270) {
        angles = 270 - angles;
      } else {
        angles = 360 - angles + 270;
      }
      $('#wheelcanvas').stopRotate();
      $('#wheelcanvas').rotate({
        angle: 0,
        animateTo: angles + 1800,
        duration: 2000,
        callback: function () {
          $('.title').text(txt)
          turnplate.bRotate = !turnplate.bRotate;
        }
      });
    };

    $('.pointer').click(function () {
      if (turnplate.bRotate) return;
      turnplate.bRotate = !turnplate.bRotate;
      //获取随机数(奖品个数范围内)
      var item = rnd(1, turnplate.restaraunts.length);
      //奖品数量等于10,指针落在对应奖品区域的中心角度[252, 216, 180, 144, 108, 72, 36, 360, 324, 288]
      rotateFn(item, turnplate.restaraunts[item - 1]);
      console.log(item);
    });
  });

  function rnd(n, m) {
    var random = Math.floor(Math.random() * (m - n + 1) + n);
    return random;

  }


  //页面所有元素加载完毕后执行drawRouletteWheel()方法对转盘进行渲染
  window.onload = function () {
    drawRouletteWheel();
  };

  function drawRouletteWheel() {
    var canvas = document.getElementById("wheelcanvas");
    if (canvas.getContext) {
      //根据奖品个数计算圆周角度
      var arc = Math.PI / (turnplate.restaraunts.length / 2);
      var ctx = canvas.getContext("2d");
      //在给定矩形内清空一个矩形
      ctx.clearRect(0, 0, 422, 422);
      //strokeStyle 属性设置或返回用于笔触的颜色、渐变或模式  
      ctx.strokeStyle = "#FFBE04";
      //font 属性设置或返回画布上文本内容的当前字体属性
      ctx.font = '16px Microsoft YaHei';
      for (var i = 0; i < turnplate.restaraunts.length; i++) {
        var angle = turnplate.startAngle + i * arc;
        ctx.fillStyle = turnplate.colors[i];
        ctx.beginPath();
        //arc(x,y,r,起始角,结束角,绘制方向) 方法创建弧/曲线（用于创建圆或部分圆）    
        ctx.arc(211, 211, turnplate.outsideRadius, angle, angle + arc, false);
        ctx.arc(211, 211, turnplate.insideRadius, angle + arc, angle, true);
        ctx.stroke();
        ctx.fill();
        //锁画布(为了保存之前的画布状态)
        ctx.save();

        //----绘制奖品开始----
        ctx.fillStyle = "#E5302F";
        var text = turnplate.restaraunts[i];
        var line_height = 17;
        //translate方法重新映射画布上的 (0,0) 位置
        ctx.translate(211 + Math.cos(angle + arc / 2) * turnplate.textRadius, 211 + Math.sin(angle + arc / 2) * turnplate.textRadius);

        //rotate方法旋转当前的绘图
        ctx.rotate(angle + arc / 2 + Math.PI / 2);

        /** 下面代码根据奖品类型、奖品名称长度渲染不同效果，如字体、颜色、图片效果。(具体根据实际情况改变) **/
        if (text.indexOf("M") > 0) {//流量包
          var texts = text.split("M");
          for (var j = 0; j < texts.length; j++) {
            ctx.font = j == 0 ? 'bold 20px Microsoft YaHei' : '16px Microsoft YaHei';
            if (j == 0) {
              ctx.fillText(texts[j] + "M", -ctx.measureText(texts[j] + "M").width / 2, j * line_height);
            } else {
              ctx.fillText(texts[j], -ctx.measureText(texts[j]).width / 2, j * line_height);
            }
          }
        } else if (text.indexOf("M") == -1 && text.length > 6) {//奖品名称长度超过一定范围 
          text = text.substring(0, 6) + "||" + text.substring(6);
          var texts = text.split("||");
          for (var j = 0; j < texts.length; j++) {
            ctx.fillText(texts[j], -ctx.measureText(texts[j]).width / 2, j * line_height);
          }
        } else {
          //在画布上绘制填色的文本。文本的默认颜色是黑色
          //measureText()方法返回包含一个对象，该对象包含以像素计的指定字体宽度
          ctx.fillText(text, -ctx.measureText(text).width / 2, 0);
        }

        //把当前画布返回（调整）到上一个save()状态之前 
        ctx.restore();
        //----绘制奖品结束----
      }
    }
  }

</script>

</html>